Vehicle-environment monitoring device

ABSTRACT

Vehicle-environment monitoring device is capable of monitoring a situation outside a vehicle. The vehicle-environment monitoring device includes an image capturing module, an image-capturing-device cover, a fan, and an air passage. The image capturing module is disposed near an inner surface of a glass member and includes a heat-generating device and an image sensor configured to capture an image of the situation outside the vehicle. The image-capturing-device cover covers the image capturing module from inside a vehicle cabin. The fan cools the heat-generating device by introducing air into the image-capturing-device cover and blows the air toward the glass member. The air passage is formed inside the image-capturing-device cover, and the air blown by the fan flows toward the glass member through the air passage.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from Japanese Patent ApplicationNo. 2018-023490 filed on Feb. 13, 2018, the entire contents of which arehereby incorporated by reference.

BACKGROUND 1. Technical Field

The present invention relates to a vehicle-environment monitoring deviceand, more specifically, to a vehicle-environment monitoring device thatmonitors the situation outside a vehicle using image sensors.

2. Related Art

In recent years, stereo-type vehicle-environment monitoring devicesusing a pair of stereo cameras, which accommodate solid-state imagesensors, such as complementary metal-oxide semiconductor (CMOS) devices,are used. In vehicle-environment recognition performed by such avehicle-environment monitoring device, images of the environment infront of a vehicle are captured with the stereo cameras, and apredetermined calculation is performed on the basis of the capturedimage data (more specifically, distance data is calculated using thetriangulation principle, and known grouping processing or the like isperformed on the distance data) to recognize objects in the capturedimages.

The stereo cameras are disposed in close proximity to the windshieldinside the vehicle cabin. Hence, when the windshield is fogged up, thestereo cameras cannot clearly capture images of the situation outsidethe vehicle and may be unable to accurately recognize the objectsoutside the vehicle.

Japanese Unexamined Patent Application Publication (JP-A) No. 2017-92736describes an invention to solve the above-described problem. In thatinvention, a housing accommodates an image sensor for capturing anoutside image through a windshield and a circuit board on which anelectronic component for processing the image data captured by the imagesensor is mounted. The housing has exhaust ports through which the heatgenerated by the electronic component is released. With thisconfiguration, the heat generated by the electronic component isreleased toward the windshield, which is included in an image capturingarea, thus preventing windshield fogging. JP-A No. 2017-92736 alsodescribes the provision of a fan for generating an airflow toefficiently conducting heat.

SUMMARY OF THE INVENTION

An aspect of the present invention provides a vehicle-environmentmonitoring device capable of monitoring a situation outside a vehicle.The vehicle-environment monitoring device includes: an image capturingmodule, an image-capturing-device cover, a fan, and an air passage. Theimage capturing module is mountable near an inner surface of a glassmember and includes a heat-generating device and an image sensorconfigured to capture an image of the situation outside the vehicle. Theimage-capturing-device cover covers the image capturing module frominside a vehicle cabin. The fan configured to cool the heat-generatingdevice by introducing air into the image-capturing-device cover and blowthe air toward the glass member. The air passage is formed inside theimage-capturing-device cover and through which the air blown by the fanflows toward the glass member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are perspective views of a vehicle in which avehicle-environment monitoring device according to an example of thepresent invention is installed, FIG. 1A illustrating the front sectionof the vehicle, FIG. 1B being an enlarged perspective view of a portionto which the vehicle-environment monitoring device is attached;

FIG. 2 illustrates the connection between components related to thevehicle-environment monitoring device according to the example of thepresent invention;

FIGS. 3A and 3B are perspective views of the vehicle-environmentmonitoring device according to the example of the present invention;

FIG. 4 is an exploded perspective view of the vehicle-environmentmonitoring device according to the example of the present invention;

FIG. 5 is a perspective view of an image-capturing-device cover of thevehicle-environment monitoring device according to the example of thepresent invention;

FIGS. 6A and 6B are perspective views illustrating air passages formedinside the image-capturing-device cover of the vehicle-environmentmonitoring device according to the example of the present invention; and

FIGS. 7A and 7B are perspective views illustrating the air passagesformed inside the vehicle-environment monitoring device according to theexample of the present invention.

DETAILED DESCRIPTION

A vehicle-environment monitoring device 10 according to an example ofthe present invention will be described in detail below with referenceto the drawings. Note that the following description is directed to anillustrative instance of the present invention and not to be construedas limiting to the present invention. Factors including, withoutlimitation, numerical values, shapes, materials, components, positionsof the components, and how the components are coupled to each other areillustrative only and not to be construed as limiting to the presentinvention. Further, elements in the following example which are notrecited in a most-generic independent claim of the present invention areoptional and may be provided on an as-needed basis. The drawings areschematic and are not intended to be drawn to scale. In the descriptionbelow, basically, the same components will be denoted by the samereference signs, and repeated descriptions thereof will be omitted. Inthe description below, the top, bottom, front, rear, left, and rightdirections will be used. The left and right are the directions as viewedfrom a vehicle 11 facing forward.

Although JP-A No. 2017-92736 describes the invention for efficientlytransferring the heat generated by the electronic component to thewindshield with the fan, specific airflow paths and other factors arenot considered. Hence, a further improvement is needed to moreefficiently prevent windshield fogging.

Another method for minimizing windshield fogging may be heating thewindshield in front of the camera using a heater patch. However, using aheater patch increases the cost. In addition, such a configurationrequires a fogging sensor for monitoring windshield fogging, which mayfurther increase the cost. Furthermore, the heater patch consumes alarge amount of power, which is problematic.

It is desirable to provide a vehicle-environment monitoring device thatcan more efficiently defog a glass member in front of the image sensor.

Referring to FIG. 1A, the vehicle-environment monitoring device 10according to this example is provided on the vehicle 11 (e.g., apassenger car). The vehicle-environment monitoring device 10 is disposednear the upper end of a windshield 12, substantially at the center inthe left-right direction of the vehicle 11. Herein, for example, thewindshield 12 is the glass member on which the vehicle-environmentmonitoring device 10 is disposed.

Referring to FIG. 1B, the vehicle-environment monitoring device 10 isdisposed behind a portion of the windshield 12 covered by a ceramic line31 that is a light shielding member at an end of the windshield 12).Image sensors 29 of the vehicle-environment monitoring device 10 areexposed to the front side from partially cut-away portions in theceramic line 31. Inside the vehicle cabin, the image sensors 29 aredisposed in close proximity to the windshield 12 to achieve a wide angleof view. Hence, the gap between the vehicle-environment monitoringdevice 10 and the windshield 12 is small, and thus, a portion of thewindshield 12 near the vehicle-environment monitoring device 10 easilyfogs up. In this example, as will be described below, fogging of thewindshield 12 is prevented by sending warm air to the gap with a fan 15,which is built in the vehicle-environment monitoring device 10.

Referring to FIG. 2, the connection between the components related tothe vehicle-environment monitoring device 10 and the like according tothis example will be described. The vehicle-environment monitoringdevice 10 mainly includes the image sensors 29, a control calculationdevice 34, an image processing device 32, a temperature detection device33, and the fan 15.

The image sensors 29 are, for example, solid-state image sensors, suchas CMOS and charge-coupled device (CCD) sensors, and capture images ofthe environment in front of the vehicle 11 through the windshield 12.The vehicle-environment monitoring device 10 according to this exampleincludes two image sensors 29, which constitute the stereo cameras.

The control calculation device 34 includes a central processing unit(CPU), a random-access memory (RAM), and a read-only memory (ROM) andcontrols the operations of the respective components of thevehicle-environment monitoring device 10. The control calculation device34 is also referred to as an electronic control unit (ECU).

The image processing device 32 is a semiconductor device that performspredetermined image processing on the basis of the image datatransferred from the image sensors 29 upon instruction from the controlcalculation device 34. The image processing device 32 is animage-processing semiconductor chip that is made of a field programmablegate array (FPGA) and is a heat-generating device that generates a largeamount of exhaust heat during image processing. In this example, bysending the air inside the vehicle cabin to the image processing device32 with the fan 15, overheating of the image processing device 32 isprevented. Furthermore, as will be described below, the windshield 12 isdefogged by sending the warm air resulting from cooling the imageprocessing device 32 to the windshield 12.

The vehicle 11 also includes the temperature detection device 33, avehicle driving unit 37, a heater 35, and a thermometer 36.

The temperature detection device 33 detects the temperature of the imageprocessing device 32. The vehicle driving unit 37 controls the drivingdevices (the engine and the motor), the brake device (the brake), thesteering device (the steering wheel) of the vehicle 11 on the basis ofthe instruction from the control calculation device 34. The heater 35heats reflection reduction members 18 (described below) and includes,for example, an electric heater. The thermometer 36 measures thetemperature of the image sensors 29. In one example, the heater 35 mayserve as a heating unit”.

The function of the vehicle-environment monitoring device 10 will bedescribed. The vehicle-environment monitoring device 10 constitutes avehicle driving assistance device. More specifically, the imageprocessing device 32 of the vehicle-environment monitoring device 10calculates distance data on the basis of reference image data andcomparison image data input from the image sensors 29, which capturesimages of the environment in front of the vehicle. The image processingdevice 32 performs known grouping processing on the distance data toextract various three-dimensional objects and the like. Herein, examplesof the three-dimensional objects include lane lines, guardrails, curbs,motorcycles, standard-sized vehicles, large-sized vehicles, pedestrians,and utility poles.

The vehicle driving unit 37 controls the driving devices, the brakedevice, and the steering device on the basis of the instructions fromthe image processing device 32 and the control calculation device 34.For example, the vehicle driving unit 37 can slow down or stop thevehicle 11 by controlling the brake device and the driving devices.Furthermore, the vehicle driving unit 37 can correct the travellingdirection of the vehicle 11 by controlling the steering device. Thevehicle driving unit 37 can also perform cruise control (adaptive cruisecontrol; ACC), in which the inter-vehicle distance is controlled, bycontrolling the driving devices, the brake device, and the steeringdevice.

The vehicle-environment monitoring device 10 defogs as follows. When auser drives the vehicle 11, the control calculation device 34 measuresthe temperature of the image sensors 29 using the thermometer 36. Whenthe measured temperature is lower than or equal to a predeterminedvalue, the control calculation device 34 heats the reflection reductionmembers 18 (described below) with the heater 35. If necessary, the fan15 is rotated to send the air inside the vehicle cabin to the windshield12. By doing so, the windshield 12 near the reflection reduction members18 is heated, minimizing fogging of the windshield 12. Thus, it ispossible to clearly capture, with the image sensors 29, images of theenvironment in front of the vehicle 11 through the windshield 12. Theheater 35 heats the reflection reduction members 18. Hence, the heater35 is away from the image sensors 29. Thus, the image sensors 29 are notheated unnecessarily.

If the temperature of the image processing device 32 measured by thetemperature detection device 33 is higher than or equal to apredetermined value, the control calculation device 34 causes the fan 15to rotate, thus sending the air inside the vehicle cabin toward theimage processing device 32. By doing so, the image processing device 32is cooled and is prevented from being overheated. The fan 15 sends thewarm air, obtained by cooling the image processing device 32, to thewindshield 12 in front of the image sensors 29. This minimizes foggingof the windshield 12, enabling the image sensors 29 to more clearlycapture images of the environment in front of the vehicle 11 through thewindshield 12. As will be described below, in this example, air passagesfor directing the warm air, obtained by cooling the image processingdevice 32, to the windshield 12 are formed.

FIGS. 3A and 3B illustrate the vehicle-environment monitoring device 10.FIG. 3A is a perspective view of the vehicle-environment monitoringdevice 10, as viewed from the upper front side, and FIG. 3B is aperspective view of the vehicle-environment monitoring device 10, asviewed from the lower rear side.

Referring to FIGS. 3A and 3B, the vehicle-environment monitoring device10 includes, from the top, a bracket 17, the reflection reductionmembers 18, and an image-capturing-device cover 14. These members areformed from, for example, a synthetic resin by injection molding. Thebracket 17 is securely adhered to the inner surface of the windshield12, and the image-capturing-device cover 14 is, for example, securelyfitted to the bracket 17. An image capturing module 13 (described below)is also securely fitted to the bracket 17.

Referring to FIG. 3A, the reflection reduction members 18 are built intothe front end, on both the left and right sides, of the bracket 17. Asviewed from above, the reflection reduction members 18 havesubstantially a triangular shape which spreads toward the front side.The vehicle-environment monitoring device 10 has two image sensors 29constituting the two stereo cameras, and the reflection reductionmembers 18 are disposed in front of the image sensors 29. The reflectionreduction members 18 block the light coming from below toward thewindshield 12 to inhibit the light from being reflected at the innersurface of the windshield 12 toward the image sensors 29. The frontsides of the reflection reduction members 18 and the vicinity thereofare substantially in tight contact with the inner surface of thewindshield 12.

Furthermore, the inner side surfaces of the reflection reduction members18 are partially removed to provide slits 19. The air having cooled theimage processing device 32 is blown out of the slits 19 and heats thewindshield 12 in front of the reflection reduction members 18. Bysending the air forward through the slits 19, the windshield 12 in frontof the image sensors 29 can be more reliably defogged.

A slight gap is formed between the windshield 12 and the reflectionreduction members 18. The air blown to the windshield 12 flows throughthe gap and returns into the vehicle cabin.

Referring to FIG. 3B, the bottom surface of the image-capturing-devicecover 14 is partially removed to form a large number of intake ports 20.The intake ports 20 are provided in a matrix. This configuration allowsfor a large opening area of the intake ports 20 while minimizinglowering of the strength of the image-capturing-device cover 14. Theintake ports 20 are disposed substantially at the center of thevehicle-environment monitoring device 10 in the left-right direction.Hence, it is possible to evenly send the air, supplied from the intakeports 20 and blown by the fan 15, in the left-right direction, thuseffectively removing and preventing the fog in front of the imagesensors 29 illustrated in FIG. 3A.

FIG. 4 is an exploded perspective view illustrating the bracket 17, theimage capturing module 13, and the image-capturing-device cover 14,which constitute the vehicle-environment monitoring device 10 describedabove, in a manner separated in the top-bottom direction.

The bracket 17 is formed of a synthetic resin plate molded into apredetermined shape. The reflection reduction members 18 are attached tothe front end of the bracket 17.

The image capturing module 13 mainly includes a module substrate 30,image capturing units 28 attached to the left and right ends of themodule substrate 30, the image processing device 32 mounted to the topsurface of the module substrate 30, and the fan 15 attached to thebottom surface of the module substrate 30.

The module substrate 30 is formed of a metal plate, such as an aluminumplate, and supports the overall image capturing module 13. The modulesubstrate 30 has a substantially rectangular shape whose longitudinaldirection corresponds to the left-right direction. In addition to theimage processing device 32 and the fan 15, other semiconductor devices,resistors, capacitors, various sensors, wiring members for coupling themone another, and the like are mounted on the module substrate 30.

The image capturing units 28 are attached to the left and right ends ofthe module substrate 30 and accommodate the image sensors 29, lenses,etc.

As has been described above, the image processing device 32 is asemiconductor device that performs predetermined image processing on thebasis of the image data obtained by the image sensors 29. For example,the image processing device 32 is disposed substantially at the centerof the module substrate 30 in the left-right direction. A radiating finfor cooling the image processing device 32 may be attached to the imageprocessing device 32.

The fan 15, which is, for example, an axial fan or a centrifugal fan,takes in the air inside the vehicle cabin through the intake ports 20and blows out the air. When the temperature of the image processingdevice 32 detected by the temperature detection device 33 is higher thanor equal to a predetermined temperature, the fan 15 is rotated to blowthe air to cool the image processing device 32.

The image-capturing-device cover 14 is a protection member that coversthe image capturing module 13 and the reflection reduction members 18from below. The left and right ends of the image-capturing-device cover14 extend forward. The left, right, and front ends of theimage-capturing-device cover 14 are aligned with the left, right, andfront ends of the bracket 17. Hence, the image capturing module 13 isaccommodated in a space surrounded by the bracket 17 and the reflectionreduction members 18. A portion of the image-capturing-device cover 14is made to project upward in a wall shape, forming an inner air-passagewall 22. The inner air-passage wall 22 forms an air passage inside theimage-capturing-device cover 14, and the details thereof will bedescribed below.

Referring to FIG. 5, the configuration of the image-capturing-devicecover 14 will be described in detail. FIG. 5 is a perspective view ofthe image-capturing-device cover 14, as viewed from the upper rear side.

Referring to FIG. 5, the image-capturing-device cover 14 has the intakeports 20 at the center in the left-right direction. A supply air passage16 extending from the intake ports 20 toward the right front side andthe left front side is formed. The supply air passage 16 is a spacedefined between an outer air-passage wall 21 and the inner air-passagewall 22. The outer air-passage wall 21 and the inner air-passage wall 22are formed by causing portions of the bottom of theimage-capturing-device cover 14 to project in a wall shape. The outerair-passage wall 21 and the inner air-passage wall 22 are continuouswith each other near the front end of the image-capturing-device cover14. Hence, the supply air passage 16 is a space that is almostcompletely enclosed by the outer air-passage wall 21 and the innerair-passage wall 22.

The width, in the front-rear direction, of the portion of the supply airpassage 16 having the intake ports 20 is larger than the width, in thefront-rear direction, of the other portions of the supply air passage16. This configuration enables a large amount of air to be introducedfrom the intake ports 20 to more effectively cool the image processingdevice 32. Furthermore, because the high-temperature air obtained bycooling the image processing device 32 can be blown to the windshield 12through the supply air passage 16, the effect of preventing fogging ofthe windshield 12 is increased.

The right-side front-end portion of the outer air-passage wall 21 isreduced in height to form a low wall portion 27. Similarly, theleft-side front-end portion of the outer air-passage wall 21 is reducedin height to form a low wall portion 26. As will be described below, theupper ends of the outer air-passage wall 21 and the inner air-passagewall 22 are in contact with the module substrate 30, the bracket 17, orthe reflection reduction members 18 to form a closed air passage, i.e.,the supply air passage 16. On the other hand, the upper ends of the lowwall portion 26 and the low wall portion 27 do not reach the modulesubstrate 30 or the other parts. With this configuration, blow-outportions, through which the air flowing through the supply air passage16 is blown toward the front side, are formed between the low wallportions 26 and 27 and the module substrate 30 and the other parts.

As has been described above, by forming the outer air-passage wall 21and the inner air-passage wall 22 on the image-capturing-device cover14, the rigidity of the overall image-capturing-device cover 14 isincreased. This minimizes the risk of the image-capturing-device cover14 being broken at the time of a collision, thus preventing injury to anoccupant due to the broken image-capturing-device cover 14.

Referring to FIGS. 6A and 6B, the details of the air passageconfiguration inside the image-capturing-device cover 14 will bedescribed. FIG. 6A is a perspective view of the image-capturing-devicecover 14, as viewed from the upper rear side, and FIG. 6B is aperspective view of the image-capturing-device cover 14, as viewed fromthe upper front side.

Referring to FIGS. 6A and 6B, an air passage 24 and an air passage 25,along which the air blown by the fan 15 flows, are illustrated byone-dot chain lines. The air passage 24 is located on the left side ofthe supply air passage 16. More specifically, the air flowing along theair passage 24 flows from the intake ports 20 toward the left side,changes direction substantially perpendicularly toward the front side,flows above the low wall portion 26, and is blown toward the windshield12 (not illustrated). The air passage 25 is located on the right side ofthe supply air passage 16. More specifically, the air flowing along theair passage 25 flows from the intake ports 20 toward the right side,changes direction substantially perpendicularly toward the front side,flows above the low wall portion 27, and is blown toward the windshield12 (not illustrated).

Referring to FIGS. 7A and 7B, the air passage 24 and the air passage 25will be described in detail. FIG. 7A is a perspective view of thevehicle-environment monitoring device 10, as viewed from the upper rearside, and FIG. 7B is a perspective view of the vehicle-environmentmonitoring device 10, as viewed from the upper front side. FIGS. 7A and7B do not illustrate the bracket 17.

Referring to FIG. 7A, the rear portions of the air passage 24 and theair passage 25 are covered by the module substrate 30 from above. Inother words, the bottom surface of the image-capturing-device cover 14,the inner air-passage wall 22, the outer air-passage wall 21, and themodule substrate 30 constitute the bottom surfaces, the front-side sidesurfaces, the rear-side side surfaces, and the top surfaces of the rearportions of the air passage 24 and the air passage 25, respectively.

The image processing device 32, which generates heat while operating, ismounted on the top surface of the module substrate 30. By forming theair passage 24 and the air passage 25 along the bottom surface of themodule substrate 30 so as to extend in the longitudinal direction, theair flowing through the air passages 24 and 25 can exchange heat withthe module substrate 30 for a longer time, thus efficiently cooling theimage processing device 32 through the module substrate 30.

The front portions of the inner air-passage wall 22 are in contact withthe bottom surface of the bracket 17 (not illustrated). The frontportions of the outer air-passage wall 21 are in contact with the bottomsurfaces of the reflection reduction members 18 (not illustrated). Withthis configuration, the front portions of the air passage 24 and the airpassage 25 are formed.

Referring to FIG. 7B, the air passage 24 extends through the slit 19provided in the inner side surface of the left-side reflection reductionmember 18 toward the top surface of the left-side reflection reductionmember 18. Hence, the air blown through the slit 19 is introduced intothe gap between the reflection reduction member 18 and the windshield 12(not illustrated). Similarly, the air passage 25 extends through theslit 19 (not illustrated) provided in the inner side surface of theright-side reflection reduction member 18 toward the gap between thereflection reduction member 18 and the windshield 12 (not illustrated).The warm air flowing through the air passage 24 and the air passage 25heats the windshield 12 in front of the reflection reduction members 18,thus preventing the fogging of the windshield 12.

The fan 15 is disposed substantially at the center of thevehicle-environment monitoring device 10 in the left-right direction. Inother words, the fan 15 is disposed substantially in the middle betweenthe image sensors 29. Hence, the amount of air flowing through the airpassage 24 and the amount of air flowing through the air passage 25 areequal, and the air heated to the same extent is supplied to the airpassage 24 and the air passage 25. Hence, even and sufficient defoggingeffects can be obtained near the respective image sensors 29.

The vehicle-environment monitoring device 10, which monitors thesituation outside the vehicle, according to this example includes: theimage capturing module 13 that is disposed near the inner surface of thewindshield 12 and that has the image processing device 32 and the imagesensors 29 configured to capture images of the situation outside thevehicle; the image-capturing-device cover 14 that covers the imagecapturing module 13 from inside the vehicle cabin; the fan 15 that coolsthe image processing device 32 by introducing air into theimage-capturing-device cover 14 and that blows the air toward thewindshield 12; and the air passage 16 that is formed inside theimage-capturing-device cover 14 and through which the air blown by thefan 15 flows toward the windshield 12. Hence, by using the fan 15, it ispossible to introduce the air inside the vehicle cabin into theimage-capturing-device cover 14 and to blow the air to the spaces formedbetween the image sensors 29 and the windshield 12 through the airpassage 16. Furthermore, this air is heated as it cools the imageprocessing device 32 and is blown to the spaces between the imagesensors 29 and the windshield 12 in this state. Hence, the fan 15 servesas a cooling fan for cooling the image processing device 32, as well asa heating fan for blowing warm air to reduce fogging of the windshield12. Hence, it is possible to prevent fogging of the windshield 12 nearthe image sensors 29 and to defog the windshield 12 if fogged. Thus, itis possible to accurately monitor the situation outside the vehicleusing the image sensors 29.

In the vehicle-environment monitoring device 10, the air passage 16 isformed by the outer air-passage wall 21 and the inner air-passage wall22, which are formed by causing portions of the inner surface of theimage-capturing-device cover 14 to project in a wall shape. Thus, theair passage 16 can be formed with a simple configuration, in whichportions of the inner surface of the image-capturing-device cover 14 arecaused to project inward in a wall shape.

The vehicle-environment monitoring device 10 further includes thebracket 17 that is attached to the windshield 12 from inside the vehiclecabin. The image capturing module 13 and the image-capturing-devicecover 14 are attached to the bracket 17. By attaching the imagecapturing module 13 and the image-capturing-device cover 14 to thebracket 17, which is attached to the windshield 12, the image capturingmodule 13 can be disposed in close proximity to the windshield 12. Thus,it is possible to obtain wide fields of view of the image sensors 29.

The vehicle-environment monitoring device 10 further includes thereflection reduction members 18 that are disposed near the image sensors29 and the windshield 12. The air blown by the fan 15 is blown intospaces between the reflection reduction members 18 and the windshield12. Hence, the reflection reduction members 18, which block the lightentering the windshield 12 from below, are disposed substantially intight contact with the windshield 12. Hence, although fog tends to begenerated in the gaps between the reflection reduction members 18 andthe windshield 12, by sending air to the gaps with the fan 15, foggingof the windshield 12 near these portions can be minimized.

In the vehicle-environment monitoring device 10, the image capturingmodule 13 includes the two image sensors 29 disposed away from eachother, the fan 15 is disposed substantially in the middle between theimage sensors 29, and the air blown by the fan 15 is blown, through theair passage 16, to the spaces between the windshield 12 and the imagesensors 29. Hence, by disposing the fan 15 substantially in the middlebetween the image sensors 29, it is possible to substantially evenlysend the air blown by the fan 15 to the spaces between the windshield 12and the image sensors 29 and, thus, to prevent fogging of the windshield12 near the image sensors 29.

The image processing device 32 of the vehicle-environment monitoringdevice 10 processes the image data obtained by the image sensors 29.Hence, although the image processing device 32 generates a large amountof heat during calculation, the image processing device 32 can beefficiently cooled by the fan 15 disposed near the image processingdevice 32. Hence, it is possible to maintain the processing speed of theimage processing device 32 constant. Furthermore, by sending thehigh-temperature air obtained by cooling the image processing device 32to the spaces between the windshield 12 and the image sensors 29, it ispossible to more effectively defog the windshield 12.

In the vehicle-environment monitoring device 10, the intake ports 20,through which the air to be blown by the fan 15 is introduced frominside the vehicle cabin, are formed by providing openings in a portionof the image-capturing-device cover 14 below the fan 15. Hence, byintroducing the air through the openings provided below the fan 15, theair can be efficiently introduced.

In the vehicle-environment monitoring device 10, the heater 35 isprovided for the reflection reduction members 18. Because the reflectionreduction members 18 are disposed in close proximity to the windshield12, the windshield 12 can be effectively heated with the heater 35.Thus, it is possible to obtain a remarkable defogging effect.

In the vehicle-environment monitoring device 10, the heater 35 heats thereflection reduction members 18 when the temperature of the imagesensors 29 measured by the thermometer is lower than or equal to apredetermined value. Because the heater 35 heats the reflectionreduction members 18 only when the temperature of the image sensors 29is low, that is, only when the temperature of the windshield 12 is lowand thus can be fogged up, unnecessary overheating by the heater 35 isprevented. Thus, it is possible to reduce the power consumption.

Although the example of the present invention has been described above,the present invention is not limited to the above-described example.

For example, referring to FIGS. 3A and 3B, the image-capturing-devicecover 14 and a rearview mirror may be formed as a single component, orthe image-capturing-device cover 14 and a rearview mirror may be coupledtogether. With this configuration, by providing the intake ports 20 inthe cover of the rearview mirror, the intake ports 20 cannot be viewedfrom the vehicle cabin. Thus, it is possible to improve the appearanceof the vehicle-environment monitoring device 10.

The invention claimed is:
 1. A vehicle-environment monitoring devicecapable of monitoring a situation outside a vehicle, thevehicle-environment monitoring device comprising: an image capturingmodule mountable near an inner surface of a window glass of the vehicle,the image capturing module comprising: a module substrate; two imagesensors attached to the module substrate, and configured to captureimages of the situation outside the vehicle through the window glass;and an image processing device attached to the module substrate betweenthe two image sensors, the image processing device being configured toprocess image data obtained by the two image sensors; and a cover thatcovers the image capturing module, the cover comprising: a surfacehaving an intake port; an inner air-passage wall projecting from thesurface, the inner air-passage wall having an end in contact with themodule substrate; an outer air-passage wall facing to the innerair-passage wall, the outer air-passage wall projecting from thesurface, the outer air-passage wall having an end in contact with themodule substrate; and a supply air passage being a space defined betweenthe outer air-passage wall and the inner air-passage wall, the supplyair passage extending from the intake port toward spaces between thewindow glass and each of the two image sensors, wherein the imagecapturing module further comprises a fan configured to introduce airinto the cover through the intake port to cool the image processingdevice with the air so that the air becomes heated air by cooling theimage processing device, and the fan is further configured to send theheated air to the spaces between the window glass and each of the twoimage sensors through the supply air passage.
 2. The vehicle-environmentmonitoring device according to claim 1, wherein the cover furthercomprises: an image-capturing-device cover that covers the imagecapturing module from below in a vehicle cabin of the vehicle, and abracket attached to the inner surface of the window glass, and the imagecapturing module and the image-capturing-device cover are attached tothe bracket.
 3. The vehicle-environment monitoring device according toclaim 1, wherein the cover further comprises reflection reductionmembers that are mounted in front of the two image sensors and that havecontact with the inner surface of the window glass, the reflectionreduction members have first portions facing to the inner surface of thewindow glass, and second portions having slits, each of the secondportions is adjacent to corresponding one of the first portions, and thefan is further configured to send the heated air to spaces between thereflection reduction members and the inner surface of the window glassthrough the supply air passage and the slits.
 4. The vehicle-environmentmonitoring structure device according to claim 1, wherein the two imagesensors are disposed away from each other, and the fan is disposedsubstantially in a middle between the two image sensors.
 5. Thevehicle-environment monitoring device according to claim 1, wherein theintake port includes an opening that is provided in a portion of thecover adjacent to the fan.
 6. The vehicle-environment monitoring deviceaccording to claim 1, wherein the cover further comprises reflectionreduction members that are mounted in front of the two image sensors andthat have contact with the inner surface of the window glass, and aheating unit is provided for the reflection reduction members.
 7. Thevehicle-environment monitoring device according to claim 6, wherein theheating unit heats the reflection reduction members when a temperatureof the two image sensors measured by a thermometer is lower than orequal to a predetermined value.
 8. The vehicle-environment monitoringdevice according to claim 1, wherein the cover further includes abracket attached to the inner surface of the window glass, and the imagecapturing module is attached to the bracket.
 9. The vehicle-environmentmonitoring device according to claim 1, wherein the fan is furtherconfigured to send the heated air through the supply air passage to thespaces between the window glass and each of the two image sensors toprevent the window glass from fogging.
 10. The vehicle-environmentmonitoring device according to claim 1, wherein the cover furtherincludes a portion having an opening, and a part in contact with theinner surface of the window glass, the portion and the inner surface ofthe window glass define a space, and the fan is further configured toblow the heated air into the space defined by the portion and the innersurface of the window glass.
 11. The vehicle-environment monitoringdevice according to claim 1, wherein the supply air passage extends in alongitudinal direction of the module substrate.
 12. Thevehicle-environment monitoring device according to claim 1, wherein thesupply air passage comprises a first portion having the intake port anda second portion other than the first portion, and a width of the firstportion is larger than a width of the second portion.